Magnetic domains refer to small differentiated magnetized areas in different directions that are produced in a spontaneous magnetization process of a magnetic material to reduce magnetostatic energy. These areas all include a large quantity of atoms, and magnetic moments of these atoms are uniformly aligned like a lot of small magnets. Because the atom magnetic moments in different adjacent areas are aligned in different directions, a magnetic domain wall is formed at a boundary between magnetic domains. A magnetic memory is a storage device for recording information by pushing a position at which the magnetic domain wall is located using a current or a magnetic field that is produced by a power supply and that is exerted on the magnetic material, to push an aligning direction of an atom magnetic moment to a magnetic domain to which the information is to be written. The aligning direction of the atom magnetic moment is related to an electron spin direction in the atom magnetic moment, and the atom magnetic moment is a vector sum of an orbit magnetic moment, a spin magnetic moment, and a nuclear magnetic moment that are of all electron sets in the atom magnetic moment.
In recent years, related theories and experiments of performing writing by pushing a magnetic domain wall using a power supply are progressively put forward and well developed, a storage speed of the magnetic memory exceeds storage speeds of a conventional flash memory chip and hard disk, and the magnetic memory receives wide attention in the market. However, in the prior art, because a magnetic domain wall cannot be fastened at a position and easily moves when driven by a power supply, data written to a magnetic domain cannot be stably pinned in the magnetic domain when driven by a power supply, and probably moves to another magnetic domain. Once the data moves to another magnetic domain whose direction is reverse to an electron spin direction of the data, data that is already written to the another magnetic domain is canceled, limiting write stability.